TypeScript's "export import" is treated as import

TypeScript has a special syntax to re-export an namespace looks like `export import <name> = <binding>`. Currently eslint-plugin-import is treating them as imports and applies incorrect rules.

```ts
// with import/order, the "export import" line will cause an error
import { Point } from "./point";
export namespace SomeNamespace {
    export import Pt = Point;
}
```